Protein Summary

This protein (YP_208650.1) is monomeric, alpha-helical in structure with a beta-sheet in the core, like a TIM barrel fold. It belongs to Pfam PF00923. Members of this family are transaldolases which can catalyze the reversible transfer of a three-carbon ketol unit from sedoheptulose 7-phosphate to glyceraldehyde 3-phosphate to form erythrose 4-phosphate and fructose 6-phosphate. Along with transketolase, this enzyme links the glycolytic and pentose-phosphate pathways. Transaldolases have well conserved sequences. The catalytic mechanism is believed to me mediated by a lysine residue which acts as a nucleophilic group to attack the carbonyl group of fructose-6-phosphate.

The comparison reveals that the proteins are similar in structure. Active site is quite conserved between YP_208650.1 (spatial location shown below in red) and 1ONR (K138=K132 resp., N160, S199, D17, N43= N154, S176, D17, D35 resp.).

It's possible that the solvent ligands EDO (green), SO4 (yellow) and HOH (blue) and Cl (grey) near the active site K138 (red) in this protein are mimicing reaction pathway and intermediates as shown below (See Ref1 for further details):

Superposition of YP_208650.1 (magenta) with 1JCJ (Ref. 1) with bound reactions intermediates in cyan and active site lysine in black: